Anemia in the pediatric patient
What Causes Thrombocytopenia (low Platelet Count)?
Key takeawaysA reduced platelet count in the blood is not always a serious problem. However, the condition affects the blood's ability to clot. If a person's blood does not clot, a wound may bleed severely. This can have serious complications in some cases.
This article examines the conditions, medications, and substances that can cause a low platelet count. It also outlines how to recognize the symptoms and what to expect from treatment.
A platelet count measures the concentration of platelets in the blood. A normal platelet count is 150,000–450,000 platelets/µl. When the number of platelets is low, this concentration reduces.
A person with thrombocytopenia will have a platelet count below 150,000/µl.
Females usually experience a platelet count that varies slightly during the menstrual cycle and can fall near the end of pregnancy.
Thrombocytopenia may make it difficult for the body to stop bleeding following an injury. Bleeding can occur inside the body, beneath the skin, or at the skin's surface.
People with thrombocytopenia usually do not experience serious bleeding until their platelet count is very low.
Two main factors cause a person to have a low platelet count: an underlying health condition or a medication. These factors can lower the platelet count by affecting the production, storage, use, or destruction of platelets.
Medical conditions that can cause a low platelet count
A low platelet count may occur due to:
Certain medical conditions can also cause a person to have a low platelet count. These include:
Pregnancy can sometimes cause a person to develop mild thrombocytopenia. The exact reason for this is unknown, but it seems to be more common close to delivery.
Medications and substances that can cause a low platelet count
Various substances can cause a person to have a low platelet count, including:
If a substance is causing a person's low platelet count, a doctor may suggest they stop taking it. Doing so should return the platelet count to normal.
If the cause is a drug a person takes for a different condition, the prescribing doctor might change the medication.
Over-the-counter (OTC) medications that can cause a low platelet count include:
Prescription medications that can cause thrombocytopenia include:
Symptoms of a low platelet count only occur at severely low levels. A count that is only slightly lower than normal may not produce symptoms.
If the count is low enough to cause spontaneous bleeding, an individual may notice minor bleeds that create small, round, dark red spots on the skin called petechiae.
Several petechiae can merge to form bruise-like rashes called purpura.
People with immune thrombocytopenia or ITP may also experience bleeding gums, nose, and blood in the urine or stools. In these cases, platelet counts are typically below 20,000/µl.
Platelets are a crucial component of the blood. They are responsible for repairing tissue damage and play a vital role in the blood-clotting system, helping stop bleeding and heal wounds. Blood clotting is also known as hemostasis.
The bone marrow produces platelets, and they are present in the blood and spleen.
How do platelets stop bleeding?
If damage occurs to the wall of a blood vessel, the vessel exposes a substance that activates platelets. Activated platelets trigger further events that bring in more platelets and a blood clot forms. This serves to plug any leak.
Activated platelets also release sticky proteins to help form the clot. A protein known as fibrin forms a mesh of threads that holds the plug together.
To diagnose a low platelet count, a doctor may begin by asking some questions and performing a physical examination. The questions might cover symptoms, family history, and medications. The examination will assess for skin rashes and bruising.
A laboratory platelet count will confirm the diagnosis, showing the exact concentration of platelets in the blood. The doctor is likely to perform other blood tests at the same time.
There are two types of bone marrow tests: a bone marrow aspiration and a bone marrow biopsy. In both tests, a doctor uses a needle to take a sample of the bone marrow for examination. Aspiration involves collecting a small amount of fluid, whereas a biopsy involves collecting some soft tissue.
A doctor may diagnose thrombocytopenia after ruling out other causes of a low platelet count.
Anyone experiencing unusual symptoms or having other concerns should discuss these with a doctor.
Platelets are components of blood cells that play a vital role in forming blood clots. If a person has a low platelet count, called thrombocytopenia, their blood might not clot properly. This can lead to symptoms such as blood loss and bruising.
Causes of a low platelet count include medical conditions and exposure to certain medications and substances, such as alcohol and quinine.
Slightly low platelet counts that do not produce symptoms may not require treatment. However, if symptoms are present, treatment may be necessary.
Treatment can involve switching medications, reducing exposure to certain substances, or treating the underlying medical condition.
Cruising For A Bruising? An Asymptomatic Patient With Low Platelets
March 18, 2025
4 min read
Clinical pearls for frontline PCPsAdd topic to email alerts
Receive an email when new articles are posted on
Please provide your email address to receive an email when new articles are posted on . Subscribe We were unable to process your request. Please try again later. If you continue to have this issue please contact customerservice@slackinc.Com.Back to Healio
A 65-year-old male presented for his annual exam.
The medical assistant (MA) checking the patient in remarked that he is asymptomatic except for reporting being a little bit more fatigued than usual. Lab work included a thyroid-stimulating hormone test, which was normal, and a complete blood count that showed a white blood cell count (WBC) of 6.5 with a normal differential, a hemoglobin of 14 and a platelet count of 95,000.
The patient denies any bleeding history or a family history of bleeding disorders. He has not had any recent illnesses, recent hospitalizations or exposure to heparin. A complete medical history shows no history of liver disease, autoimmune disorders, immune deficiency disorders, malignancies, organ transplant or heart valve surgery. He also denies any history of hematochezia, epistaxis or bruising, in addition to no weight loss, fevers or pain.
The patient is a nonsmoker and drinks two glasses of wine per week or less, with no other alcohol use. His medications include lisinopril 10 mg daily and venlafaxine 150 mg twice daily. He denies taking any aspirin, NSAIDs or other over-the-counter medication. He received COVID-19 and influenza vaccines about 1 month before this visit. His hobbies include water skiing and mountain biking.
A review of the patient's chart shows that he had a CBC that was normal — including a platelet count of 180,000 — about 5 years ago before a hernia surgery. He received treatment at an urgent care facility about a year ago, where he had a normal CBC, except for a platelet count of 110,000.
Enlarge Purpura and petechiae are two types of bruising that are common in individuals with thrombocytopenia. Derived from NHLBI. A physical examination showed a normal, healthy-appearing 65-year-old man. No evidence of bleeding, ecchymosis, petechiae, lymphadenopathy or heart murmurs were noted. A liver exam did not show evidence of an enlarged liver. A repeat CBC showed a hemoglobin of 14.2, a WBC of 6.8 with a normal differential and a platelet count was 95,000. A call to the pathologist asking her to review the slide showed no evidence of large or clumped platelets. The physician decided to repeat the CBC in about 6 weeks, and it returned showing hemoglobin of 13.8, a WBC of 6.5 with a normal differential and a platelet count of 90,000. Philip A. Bain The physician told the patient he was unsure about the cause of the persistently low platelets and recommended that he be seen by a hematologist to sort out the cause. The hematologist believed that the patient was in no immediate danger and that he should have his platelets rechecked every 3 to 6 months. The primary care physician continued to check the CBC every 3 months. It showed a gradual decline in his platelet count with the other two cell lines remaining normal over the course of the next 12 to 15 months. The patient was scheduled for a total hip replacement, and his preoperative labs showed a platelet count of 55,000. The patient was seen again by the hematologist who believed that he likely could tolerate the surgery but that the platelet count had become an emerging concern. The hematologist made the diagnosis of immune-mediated thrombocytopenia and recommended treatment of the disorder with steroids prior to any consideration of his elective surgery. The patient completed an 8-week course of steroids, and his platelet count improved to 130,000. At that point, the hematologist believed that the patient could go ahead with the elective surgery. Lessons learned Thrombocytopenia is a relatively common finding in primary care. A normal platelet count is 150,000 to 450,000. Thrombocytopenia is diagnosed when the platelet count is less than 150,000. Platelet counts 100,000 to 150,000 are called mild thrombocytopenia. Counts of 50,000 to 90,000 are termed moderate thrombocytopenia, and a platelet count of less than 50,000 is generally referred to as severe thrombocytopenia. Patients with platelet counts in the mild range (100,000 to 150,000) are usually asymptomatic without evidence of bleeding, petechiae, purpura or ecchymosis. Patients with platelet counts in the 20,000-to-50,000 range often will show signs of ecchymosis, petechiae or purpura. When the platelet count drops below 50,000, it is usually advised that the patient postpone elective surgery, if possible, until the cause and treatment options of the low platelet count are considered. Patients with platelet counts of less than 10,000 are at high risk for serious bleeding complications, including internal bleeding. The main causes of a low platelets include decreased production of platelets, increased destruction of platelets, splenic sequestration of platelets, dilutional thrombocytopenia and clumping (usually termed pseudothrombocytopenia). In general, low platelets can be associated with bleeding or bruising, but certain causes of low platelets are associated with bleeding and thrombosis. Examples include antiphospholipid syndrome, heparin-induced thrombocytopenia and the thrombotic microangiopathies like thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS). Patients with isolated low platelets (ie, have normal WBC and hemoglobin) without significant systemic illness usually have immune thrombocytopenia or medication-related thrombocytopenia. Immune thrombocytopenia is a diagnosis of exclusion. An important first step in evaluating stable outpatients with mild to moderate thrombocytopenia is to rule out pseudothrombocytopenia due to clumping of platelets. This can be done by asking the lab to collect blood in a heparin sodium citrate tube to rule out clumping effect. It is important for PCPs to always repeat a CBC if mild to moderate thrombocytopenia is found before pursuing a hematology consultation to confirm that it is persistent. The next step is to sort out if the low platelet condition is acute or chronic by reviewing old CBCs. Common emergency causes generally require hospitalization to prevent further complications and hasten diagnosis. These include heparin-induced thrombocytopenia, one of the thrombotic microangiopathies (TTP, HUS), hemolysis, significantly abnormal liver function tests and hemolysis, elevated liver enzymes, low platelet count in pregnant patients. Common nonemergency causes include immune thrombocytopenia, medication-associated thrombocytopenia and liver disease. References : Add topic to email alerts Receive an email when new articles are posted on Please provide your email address to receive an email when new articles are posted on . Subscribe We were unable to process your request. Please try again later. If you continue to have this issue please contact customerservice@slackinc.Com. Back to HealioCan Multiple Myeloma Cause Thrombocytopenia (Low Platelet Counts)?
Thrombocytopenia can put you at risk of severe bleeding. This can be external bleeding, like a wound that won't stop bleeding. It can also be internal bleeding, like a brain bleed that doesn't clot and stop.
In either situation, this complication of thrombocytopenia requires urgent medical care. Without treatment, this bleeding could be fatal.
Comments
Post a Comment